Therapeutic, Humanized Monoclonal Antibody Exhibits Broad Binding and Protective Efficacy against Acinetobacter baumannii.

Acinetobacter baumannii is an extremely drug-resistant pathogen necessitating the development of new therapies. We seek to generate a cocktail of monoclonal antibodies (MAbs) that can target the full diversity of A. baumannii isolates. We have newly identified the antibody MAb5. Here, we demonstrate that MAb5 has broad binding against U.S. ( n  = 300) and international ( n  = 250) isolates (72.24% and 28.76%, respectively), likely targets O-antigen capsular carbohydrates, and exhibits protective efficacy in vivo .